Studies include an investigation of the alterations produced in the Salmonella cell surface by certain temperate bacteriophages; we are specifically studying the function and control of viral specific membrane proteins and their interaction with polyisoprenoid lipids. A second problem which is related to the above is a study of the mechanism of phage infection in Salmonella including the adsorption process ejection of viral DNA and its penetration into the cell. A third problem is a study of the association of the bacterial chromosome with the cell membrane, the aim being to understand the process by which chromosomes are segregated during cell division. At present we are carrying out an analysis of membrane proteins associated with isolated folded chromosomes.